Steam systems are used for heating in a wide variety of industrial, commercial, and residential applications. As heat is transferred from the steam to the surroundings, condensation occurs and liquid condensate is formed within the steam line. The presence of condensate in a steam line reduces the heat transfer efficiency and also causes mechanical and corrosive damage. Accordingly, all steam systems include some mechanism for removing condensate.
Condensate removal systems typically contain a number of devices placed at low points in the system that allow condensate to leave the steam line and pass through condensate lines that run to a condensate receiver. There are two basic types of condensate removal devices. Devices of the first type permit the periodic flow of condensate and are commonly known as steam traps. The periodic flow devices usually contain a thermostatically-controlled valve that detects the accumulation of cooled condensate and opens to allow the condensate to flow out of the steam line. A common example of such a device is the steam trap located near the bottom of steam radiators used for space heating. The primary disadvantage of periodic flow devices is that they have moving parts that eventually fail and must be replaced.
Condensate removal devices of the second type feature a restricted passageway through which condensate continually flows. Continuous flow devices have no moving parts to fail. However, the sizing of the passageway is critically important. If the passageway is too small, condensate builds up in the steam line. If the passageway is too large, excessive amounts of steam escape with the condensate. Optimal sizing of a passageway for a given application is very difficult to predict. Even with accurate and abundant information concerning the particular application, it is often necessary for the sizing of the passageway to be changed from the original prediction.
LeBlanc, U.S. Pat. No. 5,120,336, issued Jun. 9, 1992, incorporated herein by reference, discloses a retrofit kit for radiator steam traps. The retrofit kit contains a nozzle body, filter screen, and spring that replace the thermostatic element, valve, and valve seat in a standard steam trap. The nozzle body fits into the condensate outlet of the steam trap and contains a coaxial venturi passage. The top of the nozzle body is positioned below the steam inlet of the steam trap so that condensate enters the venturi passage tangentially and so that airlock at the entrance of the venturi passage is avoided. Because radiators and radiator steam traps are of many different sizes and capacities, the LeBlanc retrofit kit is sold with over one hundred different nozzle body sizes. The LeBlanc retrofit kit is also sold with many different sizes of screens and springs.
Accordingly, a demand exists for an improved continuous flow retrofit kit for radiator steam traps. In particular, a demand exists for such a retrofit kit that requires only a small number of different parts to fit the many different radiators and radiator steam traps that are in use.